An evaporator or a condenser commonly includes a multiplicity of tubular circuits, formed from a series of parallel U tubes connected to each other through bent tube sections in such a way as to provide a serpentine path in each tubular circuit, with fins through which these circuits pass. The fins are substantially parallel to the tubes and are in heat conductive contact with them. The conventional evaporator or condenser also has a fluid distributor assembly connected to one end of the said circuits and a fluid collector assembly connected to their other end. The fluid is for example a refrigerant fluid of the fluorocarbon type.
In addition, in such an evaporator, the tubular circuits are disposed in such a manner that the segments of the parallel U tubes which form part of the said circuits are grouped in an arrangement which is such that the said segments are either juxtaposed to each other or superimposed upon each other. This arrangement is necessary in order to obtain the required change of state of the refrigerant fluid in the tubular circuits such that, after heat exchange with another fluid such as ambient air passed through the evaporator, the refrigerant fluid reaches the outlet ends of the tubular circuits in a second state changed from the initial state in which it was introduced into the evaporator.
To this end, the fluid distributor assembly commonly includes a delivery tube which is connected through narrow or capillary tubes to the input ends of the tubular circuits, in such a way that the fluid is then distributed in substantially equal quantities to each circuit.
Conventionally, the fluid is removed from the evaporator by collecting means which comprises a hollow collecting cylinder closed at its ends, with a general axis which is perpendicular to the outlet ends of the circuits. The circumferential wall of the collecting cylinder is formed with bores in which the outlet ends of the tubular circuits are sealingly fixed, together with another bore in which a suction tube, for removal of the fluid, is also sealingly fixed. Such an arrangement is described in U.S. Pat. No. 2 088 254.
Certain disadvantages have been found to exist in this conventional fluid collecting means when used for removing the fluid from an evaporator or condenser in a vehicle. The fluid arriving in liquid form at the input ends of the tubular circuits leaves in the form of a gas via the outlet end of the said circuits, and enters the hollow collecting cylinder at a high velocity, so that when it impinges on the internal wall surface of the latter, noise and vibrations are set up which can be transmitted back through the evaporator. Since the evaporator is arranged close to the interior or passenger compartment of the vehicle, these noises and vibrations can thereby be transmitted into the passenger compartment.
In addition, conventional fluid collectors waste energy in the fluid, thus creating a loss of pressure and, in extreme cases, involving the danger that the change of state of the fluid may not be complete at the outlet end of the evaporator circuits, so that there can then be a mixture of the fluid in different states. Such a mixture at this stage is inadmissible.